Motor control.



I Witnesses:

w NAUMANN.

MOTOR CONTROL.

APPLICATION FILED MAR. 10, 1911.

1,036,688. Patented Aug127, i912.

R FORWARD 3 2 R, I 1 l fvfiWlfifl I 5 I 3 E I I F l 4 I I i c I l I 7 In- A I REVERSE r 6 I REVERSE Inventor:

% X/ Wilhelm n ni-ann,

His jlttorney UNITED STATES PATENT OFFICE;

'WILHELM NAUMANN, OF PANKOIV, GERMANY, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

MOTOR CONTROL.

To all whom it may concern:

Be it known that I, WVILHELM NAUMANN, a subject of the King of Prussia,residing at Pankow, Germany, have invented certain new and usefulImprovements in Motor Control, of which the following is aspecification.

This invention relates to the control of electric motors and has for itsobject the provision of means whereby an electric motor may be started,stopped, and generally controlled in a reliable and efficient manner.

My invention relates more specifically to the type of motor control inwhich provision is made for stopping the motor by causing it to act as agenerator to retard the rotation sistance.

of the armature by a braking effect.

My invention is particularly applicable to motors intended forreversing, the arrangement being such that the motor willbeautomatically braked when the motor circuit is opened to stop the motorwhen running in either direction.

In carrying out my invention in one form, I provide the motor with apermanent shunt field and two series fields, one for each direction ofrotation. connected one to each side of the armatureand have aresistance connected in series therewith for starting. I also provide acontroller for cutting out the starting re- T his controller may bearranged to short circuit the series field when the motor gets up tospeed. A reversing switch is likcwise provided for directing the current through the motor for opposite. directions of rotation. The switchwhich controls the motor circuit is so arranged that when it is opened,a braking circuit is-establish'ed through the armature and the fieldwhich has been inactive, the other field being short circuited so thatthere is always an inactive or decnergizing field ready for connectingin circuit with the armature for braking when the switch is opened.

In the accompanying drawing in which I have disclosed my inventionembodied in concrete form for purposes of illustration, A represents thearmature of a reversible motor and F and F the two series.fieldsconnected thereto. The fields are connected one on each side of thearmature.

S represents a shunt field of the motor which is permanently connectedacross the line. In series with the field F are two sec- Specificationof Letters Patent.

Application filed March 10, 191

These fields may be Patented Aug. 2'7, 1912.

Serial No. 613,616.

tions of resistance R, It and similar resistances R R in series with thefield F. The controller C is arranged when moved in the forwarddirection to cut out resistance sections R and R step by step andfinally short circuit the field F when the controller is in the positionmarked 4. Similarly, when the controller is moved in the reversedirection the sections of resistance R R are cut out and finally thefield F shortcircuited. A reversing switch B is arranged so as toconnect the current. either through the field F and its attachedresistances or the field F for opposite directions of rotation. thedirection of current through the armature in each case being reversed.

The switch for opening and closing the motor circuit I have shown as asolenoid switch D arranged to bridge contacts 1 when energized andbridge the contacts 2 when deene'rgized. This solenoid is controlled bythe control switch E. One of the contacts 2 is connected with anadjustable member G of the resistance R, while the other is connectedwith the member G of the resistance R As thus constructed and arranged,the operation of my device is as follows: \Vhen the switch E is closedand assuming that the reversing switch B is set for forward movement andthe controller C in the starting position for forward movement, thesolenoid D is energized and the contacts 1 are bridged, therebycompleting a circuit from the line L across the contacts 1, through thecontact fingers 3, 4: on the reversing switch B, through the resistancesR R, field F, armature A, controller fingers 5, 6 and conductor 7 backto line L. As the controller C is moved to the second position theresistance R is short rircuited and when it is moved to the thirdposition the resistance R is short circuited. 'hen the controller ismoved to the last forward position, the field F, which has beenconnected in series with the motor armature for starting, is shortcircuited. The motor is now normally running in the forward direction,the parts being in the position shown in the drawing. If now the switchE is opened to stop the motor, contacts 2 will be bridged. This causes abraking circuitto be establishedthrough the armature from the upperbrush through the controller contacts which short circuit the field F,portion of resistresistance R determined-b the Josition of the movablemember G','fie .d F and back to the armature. That causes the armatureto generate a current which acts as a dynamic brake to stop the rotationof the armature. The amount of braking efi'ect maybe varied by movingthe members G and G. W hen the reversing switch 35 is thrown to theopposite position, the current through the armature is reversed and thefield F is energized in series with the armature and with theresistances {R and R Thee'e resistances are then cut out by the movementof thecontroller in the reverse direction until the field l?" is shortcirc'uited. @n opening the motor circuit at the switch E, the brakingcircuit is again established.

- It will thus be seen that .1 have provided a convenient and efficientarrangement for starting and quickly stopping an electric motor runningin'either direction, and while l have disclosed my invention as embodiedin concrete form for purposes of illustration, it should be understoodthat I do not limit a my invention thereto, since various modificationsthereof will suggest themselves to those skilled in the art withoutdeparting from the spirit of my invention, the scope. of which is setforth in the annexed claims.

W hat I claim as new and desire to secure 7 by Letters Patent of theUnited States, is,

1. The combination with a reversible electric motor having a shunt-fieldand two 58-.

ries fields, one for each direction of rotation, of a' switch in themotor circuit, and connections whereby when said switch is opened abraking circuit is completed through the armature and one field.

2. The combination with areversible electric motor having a shunt fieldand two series fields, one foreach direction of rotation, of acontroller for said motor arranged to short circuit one or said fieldsduring'normal running, a switch in the motor circuit,

. and connections whereby. a braking circuit is "completed through thearmature and the other fiel d when said switch is opened.

8. The combination with an electric motor having a shunt field and twoseries fields, one-connected to each side of the armature of said motorfor opposite directions ot-rotation, of a switch in the motor circuit,and connections whereby when said switchisopened va-braking circuit iscompleted through the armature and one of said fields while the otherfield is short circuited. Q a

t; =5lhe combination with a reversible electri'c motor "having a shuntfield and two seriesfields, of a reversing switch arranged to I energizeeither of said fields for opposite directions of rotation, a switchinthe motor circuit, and connections. whereby a braking circuit iscompleted through the armature nections whereby a braking circuit isestablished through the noaaess and the 'deenergized field when saidswitch is'opened.

5. The combination with a'reversible electricmotor having a shunt fieldand two se; ries fields, one connected to each side of the armature foropposite directions or rotation, a resistance in series with each ofsaid fields, a controller for cutting out one of said fields and theresistance connected thereto to bring the motor to running speed in eachdirection, a switch in the motor circuit, and connections whereby abraking circuit is established throughthe armature and the other fieldwhen the switchfis opened.

6. lhe combination with a reversible electric motor having a shunt fieldand two series field's a reversing switch arranged to energize eitherot'said fields for opposite directions of rotation, a resistance inseries with each field, a controller forcuttin out one field andtheresistance connected t ere to, a'switch in the motor circuit, andconwhen said switch is opened armature and the other field.

'2'. The combination with a reversible elec-" tric motor, ot'a startingresistance connected with each side of the armature, a controllerarranged to cut out one ofsaid resistances ,when moved in one dlrectibnand the other resistance when moved in the opposite direction, and areversing switch for changing. the'dir'ectionj of current through saidmotor.

8." The combination with an electric niotor having a shunt field and twoseries fields,

one connected to each s'ideiof the armature, of a starting resistanceconnected to each field, and a controller arranged to cut out one fieldand the resistance connected thereto when moved in each direction, and areversing switch .tor changing the direction of current through saidmotor.

j9."lthe combination with an electric mo tor of a starting resistanceconnected with eac side of the armature, .a controller arranged to cutout one"- of said resistances when moved in-one direction and the otherresistance when moved in the .opposite .direction, a reversing; switchfor changing the direction of the current through said motor, a switchin themotorcircuit, and connections whereby when the said switch isopened a braking circuit is established through "the armature and one ofsaid re sistances' lb. The .coinbii'ia-tion with a reversible 2 electricmotor havinga shunt field of a'se; rie's field connected to each sideoft e arma-.

each field, a controller arranged to cut outone otsaid resistances, andavfield connected thereto when moved in each direction, a reversing"switch for changing. the direction of ture and a starting resistanceconnected to- .15 '7 for, and means for connecting either of said motorCiI'Clllt, and. connections whereby when said switch is opened a'brakingcircuit is established through the armature'and one of said resistances,

11.- The combination with a motor, of two separate series field windingstherefor, a supply circuit, means for connectin armature of the motorthrough one 0% said field windings to the supply circuit, and means,operating when said circuit is opened to -short- 'c1rcuit said armatureupon itself through the other. of said field windings.

12. The combination with a motor, of a pair of separate series fieldwindings therefield windingsin" either an operating or the brakingcircuit, including the armature of: the motor.

13. The combination with a motor, of a pair of separate series fieldwindings therefor, means for connecting said field windings alternatelyin series with the armature of the motor in the operating circuit, andmeans for connecting either of said 'field windings in a braking circuitalso including said armature. i

In witness whereof, I have hereunto set my hand this 15th day ofFebruary, 1911.

VVILHELM NAUMANN.

Witnesses FnEDRIcK GICI-IBY, LEOPOLD FANISCH.

" Gopiesiot this patent may be obtained for five cents each, byaddressing the Commissioner or Patents,

' Washington, D. 6.

